The present invention relates to an exothermic composition for reparing steelmaking furnaces and the like. Such composition may be applied either in the form of a gunning mix or in the form of pitch bonded briquettes. In some respects the present invention represents an improvement over the disclosure by U.S. Pat. No. 3,086,876 "Refractory Composition and Process of Making the Same". However, such material is not adopted for gunning use.
As is well known to those skilled in the art, the refractory linings of steel making vessels and others such as open hearths, electric furnaces, and basic oxygen furnaces, not only are subject to severe erosion during use but also erode unevenly. In order to compensate for and repair such uneven wear and to provide for maximum furnace lining life, the firebrick lining which is normally used in such vessels, is protected in the heavy wear areas by spraying with loose refractory materials containing relatively low temperature bonding composites that causes it to adhere to the brick lining. These composites with the refractory material are usually applied by what is referred to as "gunning" and are presently commercially available in main categories referred to as either silica or phosphate or chromite bonding materials plus lesser known composites. These composites are fluid and thus "wet" the granular refractories when mixed with water.
As is also known to those skilled in the art, practically all large steelmaking vessels use a lining of basic magnesite or magnesite-dolomite brick or the like. To repair such linings, the usual gunning materials, until the advent of this invention, were of a similar basic composition. Such gunning materials are normally of a very fine size.
We have discovered that, by using the gunning mix of the present invention, very desirable furnace repair results are obtained and that by using such combination of materials, furnace lining life has been markedly extended.
We have also discovered that when the present exothermic compositions are applied in the form of pitch bonded briquettes to the floor of steel making furnaces excellent lining repair is accomplished.
Accordingly, a principal object of our invention is to provide a novel exothermic composition for repairing the linings of steel making furnaces and the like.
Another object of our invention is to provide a novel gunning composition for repairing the refractory walls of steelmaking furnaces and the like.
Another object of our invention is to provide a novel composition for repairing the refractory linings of steelmaking furnaces consisting essentially of exothermic patching material in combination with other selected material.
Still a further object of our invention is to provide briquettes of our materials.
Still another object of our invention is to provide a process for repairing refractory linings employing the present novel compositions.
These and other objects, features and advantages of our invention will become apparent to those skilled in this particular art from the following detailed disclosure thereof.